Recently, with improvements in communication environments and advances in information communication techniques, information providing services and information using services which use computer networks such as the Internet can be provided. In multimedia environments in which all data, e.g., text data, image data, and sound data, are digitized, in particular, since information can be shared and provided, many information providing services have been offered through the Internet.
Creating the image input by a digital camera or scanner as electronic data and storing the data in a recording medium such as an HDD, CD-R, or the like of a personal computer have already become general operations.
As described above, with rapid improvements in Internet connection environments (improvements in communication environment and the function of connection devices and reductions in cost), there have appeared application service providers (to be referred to as photosites hereinafter) which provide services like keeping the image data photographed by users using image input devices in storage areas in servers on the Internet and allowing the users to browse the image data again at the time they require it or processing the image data, and print service providers (to be referred to as printsites hereinafter) which provide services of printing electronic documents such as the New Year's cards, wordprocessed documents, and images.
In these photosites, a system is generally constructed in which an access code of some kind is added to the image uploaded (transferred) by a user to allow a user who inputs the access code to browse the image.
On the photosite, when an access code is input, a database is searched for an image corresponding to the access code. If the image is found, the image is displayed. Some user who does not know the access code for the image may try to illicitly see the image by randomly inputting access codes for mischief or curiosity. In order to prevent the unspecified third party from accessing the image by using such illicit operation, for example, setting of a password is generally allowed in correspondence with an access code on the photosite side. An image for which a password is set cannot be browsed unless the proper password is input, thus allowing only authorized users to browse the image.
As described above, images can be protected against unauthorized access by the method of protecting image browsing by using passwords or the like. However, a user who tries to illicitly access an image by inputting access codes for mischief and curiosity inputs many access codes and/or passwords in a short period of time, expecting casual coincidence. In the photosite, every time a password is input, a database is accessed to check whether the input value is correct or not. If, therefore, many passwords are input in a short period of time, the database is frequently accessed, resulting in a deterioration in the performance of a server computer (photosite server) as a component of the photosite server.